Mechanical Fatigue Testing of Thermal Spray Coated Specimens: A Summary of Recent Developments

Cyclic, mechanical fatigue testing of coated materials has increased with the wider use of thermal spray coatings on components experiencing fatigue loading. Fatigue testing of coated specimens presents all of the difficulties associated with fatigue testing of uncoated specimens and several difficulties that do not arise when testing uncoated specimens. A summary of fatigue test methods and test specimen geometries for both coated and uncoated specimens is presented. Issues of specimen standardization, geometry, substrate preparation, and post-spray surface finishing are discussed. Several specimen configurations are described.